Jenkinsfile: don't delete pods during teardown
    
    The pods will be automatically deleted by OpenShift when we delete the
    associated deployment. If we try to explicitly delete the pods
    ourselves, it will occasionally fail due to a race condition (we try to
    delete the pod but it's already gone):
    
        ERROR: Error during delete;
        {reference={}, err=Error from server (NotFound): pods "waiverdb-test-jenkins-waiverdb-49-web-1-jqs0a" not found, verb=delete, cmd=oc delete dc,deploy,pod,configmap,secret,svc,route -l environment=test-jenkins-waiverdb-49 --server=https://open.paas.redhat.com/ --namespace=waiverdb-test --token=XXXXX , out=deploymentconfig "waiverdb-test-jenkins-waiverdb-49-database" deleted
        deploymentconfig "waiverdb-test-jenkins-waiverdb-49-web" deleted
        pod "waiverdb-test-jenkins-waiverdb-49-database-1-x6dka" deleted
        pod "waiverdb-test-jenkins-waiverdb-49-web-1-raf5x" deleted
        configmap "waiverdb-test-jenkins-waiverdb-49-configmap" deleted
        secret "waiverdb-test-jenkins-waiverdb-49-secret" deleted
        service "waiverdb-test-jenkins-waiverdb-49-database" deleted
        service "waiverdb-test-jenkins-waiverdb-49-web" deleted
        route "waiverdb-test-jenkins-waiverdb-49-web" deleted, status=1}